NaCl kept roads free from slippery ice, but it also changed the nature of North America's freshwater lakes.
Extrapolating that finding for all of North America, at least 7,770 lakes are at risk of elevated salt levels — a likely underestimate, the researchers said.
No federal body tracks how much salt gets spread on our roadways or makes its way into our lakes.
Impervious surfaces, critically, allow dissolved salt to slide into lakes rather than soaking into soil.
Across all lakes, chloride concentrations ranged from 0.18 to 240 milligrams per liter, with a median of 6 milligrams per liter.
Some municipalities have improved how they manage salt by tweaking the rate at which trucks dump salt on roads, for example.
“There’s a lag after stopping laying down salt — a lot of salt is stored in soils,” Dugan said. »
